Biomarkers · Cardiac & Hemodynamics
PR Interval
Lower values go with lower risk of death. Not measured in our NHANES panel. The curve is drawn from the published study (source below).
PR Interval and risk of death
Published curve higher than the NHANES fitNHANES fit higher
Risk of death relative to the curve's reference value, drawn from the published study (source below).
What studies found when this marker was changed
They describe what happened in those study groups, not a recommendation. See all catalogued interventions.
Measured changes in PR Interval, study by study
3 effects with a numeric size, each from one study arm: the dot is the reported change, the line its 95% interval where one was given. Green points move the marker the way lower risk of death lies; amber the other way. Study results in the groups studied, not predictions for a person.
| Type | Intervention | Reported effect | Evidence | Source |
|---|---|---|---|---|
| pharmacologic | Adjunctive lacosamide 400 mg/day (maximum recommended dose) for 12 weeks maintenance in adults with partial-onset seizures | Mean PR interval change +4.4 ms with 400 mg/day (vs -0.3 ms placebo; +1.4 ms at 200 mg, +6.6 ms at 600 mg) after 12 weeks | RCT | Rudd GD, et al. Acta Neurol Scand. 2015. Lacosamide cardiac safety: clinical… |
| pharmacologic | Diltiazem 240 mg per day for prophylaxis of Prinzmetal's (variant) angina | PR interval increased 3% at the 240 mg/day dose; no change in blood pressure or heart rate | RCT | Schroeder JS, et al. Am J Med. 1982. Multiclinic controlled trial of diltiazem… |
Things that worsen it
| Type | Condition or exposure | Reported effect | Evidence | Source |
|---|---|---|---|---|
| pharmacologic | Etrasimod (S1P receptor modulator) multiple ascending doses 2-4 mg daily for 14 days vs placebo in healthy adults (thorough QT study) | PR interval lengthened by up to 6.6 ms vs placebo (largest by-time-point placebo-corrected change) over 14 days of etrasimod 2-4 mg | RCT | Darpo B, et al. Clin Pharmacol Drug Dev. 2024;13(4):326-340. |
What else moves this marker
They describe those study groups, not an individual, and an association is not a cause.
Diseases and conditions
| What | Effect on the marker | Comparison · population | Source |
|---|---|---|---|
| ↑ Intrahepatic cholestasis of pregnancy (fetal PR interval) · fetuses of affected pregnancies vs healthy pregnancies | +10.1 ms (95% CI 7.34 to 12.86) | fetuses in pregnancies with intrahepatic cholestasis vs healthy pregnancies · Fetuses assessed by fetal echocardiography in 10 studies (14 studies reviewed) | meta analysis · PMID 37023984 |
| ↑ Severe vs mild intrahepatic cholestasis of pregnancy (fetal PR interval) · severity gradient within affected pregnancies | +5.98 ms (95% CI 0.2 to 11.77) | severe vs mild intrahepatic cholestasis of pregnancy · Fetuses in pregnancies complicated by mild or severe intrahepatic cholestasis | meta analysis · PMID 37023984 |
Genetic predisposition
| What | Effect on the marker | Comparison · population | Source |
|---|---|---|---|
| ↑ SCN5A rs3922844 (African ancestry) · per minor allele, African American adults | +5.1 ms per allele (95% CI 4.1 to 6.1) | per copy of the rs3922844 minor allele · 6247 African American individuals from four cohorts | gwas · PMID 21347284 |
| ↑ SCN5A rs3922844 (European ancestry) · per minor allele, European-ancestry adults | +2.4 ms per allele (95% CI 1.8 to 3) | per copy of the rs3922844 minor allele · 14,042 individuals of European ancestry | gwas · PMID 21347284 |
Environmental and occupational exposures
| What | Effect on the marker | Comparison · population | Source |
|---|---|---|---|
| ↓ Fever (in Brugada syndrome) · febrile state vs the same patients at baseline | -21 ms | during fever (148 +/- 45 ms) vs baseline (169 +/- 29 ms) · Patients with fever-induced Brugada syndrome; paired ECG subgroup (n=52) with ECGs at baseline, during fever and after drug challenge | cross sectional · PMID 27033637 |
Sources
- Risk curve: Kwok 2016 (PMID 26879241): all-cause RR 1.24 (1.02-1.51) prolonged vs normal PR interval (pooled adjusted studies, five studies). Scaled to published population values.
- Kwok et al. Prolonged PR interval, first-degree heart block and adverse cardiovascular outcomes: a systematic review and meta-analysis. Heart (British Cardiac Society). 2016;102:672-80.
Map PR Interval against another biomarker.
Related markers: Abdominal Aortic Calcification (AAC) · Ankle-Brachial Index (ABI) · Cardiac (Valvular/Annular) Calcification · Carotid Intima-Media Thickness (CIMT) · Carotid-Femoral Pulse Wave Velocity (PWV) · Copeptin · Coronary Artery Calcium Score (Agatston) · Corrected QT Interval (QTc)